definitions

Question 1

law of conservation of charge

Answer 1

the net charge of an isolated system remains constant during any physical process.

Question 2

coloumbs law

Answer 2

two point charges in free space or air exert forces on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges

Question 3

ferrromagnetic

Answer 3

a metal that can be magnetised

Question 4

magnetic field

Answer 4

a region in space in which a magnet or ferromagnetic material will experience a force which is magnetic in nature.

Question 5

curie temperature

Answer 5

the temperature to which a magnet must be heated to change the alignment of the domains (which are themselves magnetic fields) of the material and hence lose its permanent magnetism.

Question 6

magnetic field line

Answer 6

An imaginary line running from N to S in which represents the direction which a compass would point if placed in that position

Question 7

potential difference

Answer 7

the work done per unit positive charge

Question 8

current

Answer 8

the rate of flow of charge

Question 9

current

Answer 9

the rate of flow of charge

Question 10

ohms law

Answer 10

current through a conductor is directly proportional to the potential difference across the conductor at constant temperature

Question 11

resistance

Answer 11

a material’s opposition to the flow of electric current

Question 12

matter

Answer 12

anything that occupies space and has mass

Question 13

pure substance

Answer 13

consist of one type of substance only and are made up either of elements or compounds

Question 14

elem

Answer 14

a substance which cannot be broken down further into simpler substances

Question 15

compound

Answer 15

formed when two or more elements combine chemically with each other in a fixed ratio

Question 16

molecule

Answer 16

group of covalently bonded atoms.

Question 17

ion

Answer 17

charged atom

Question 18

cation

Answer 18

positively charged ion

Question 19

anion

Answer 19

negatively charged ion

Question 20

atomic number

Answer 20

number of protons in an atom

Question 21

isotope

Answer 21

atoms of the same element which have different mass numbers

Question 22

mass number

Answer 22

number of protons plus neutrons in an atom

Question 23

mixture

Answer 23

combination of two or more substances in which the substances retain their own properties.

Question 24

heterogeneous mixture

Answer 24

mixture in which the composition of the mixture is not uniform

Question 25

homogeneous mixture

Answer 25

mixture in which the composition of the mixture is the same throughout and consists of two or more substances in the same phase

Question 26

suspension

Answer 26

any combination of substances that do not dissolve in one another results in a heterogeneous mixture

Question 27

miscible

Answer 27

liquids that mix completely with each other

Question 28

solution

Answer 28

homogenous mixture of solute and solvent

Question 29

solvent

Answer 29

substance in which another substance is dissolved, forming a solution

Question 30

solute

Answer 30

substance that is dissolved in the solution

Question 31

atomic radius

Answer 31

the radius of the atom, from the nucleus to the outermost electrons

Question 32

ionisation energy

Answer 32

the energy required to remove one electron from a single atom in the gaseous phase.

Question 33

first ionisation energy

Answer 33

the energy required to remove the first electron from a single atom in the gaseous phase.

Question 34

electron affinity

Answer 34

amount of energy liberated when an electron is added to a single atom in the gaseous phase.

Question 35

ionic bond

Answer 35

transfer of electrons and subsequent electrostatic attraction

Question 36

covalent bond

Answer 36

sharing of at least one pair of electrons by two non-metal atoms

Question 37

electronegativity

Answer 37

a measure of the tendency of an atom to attract a bonding pair of electrons

Question 38

metallic bonding

Answer 38

being between a positive kernel and a sea of delocalised electrons

Question 39

temperature

Answer 39

measure of the average kinetic energy of the particles of a substance

Question 40

melting point

Answer 40

the temperature at which a solid changes phase to a liquid

Question 41

Freezing point

Answer 41

the temperature at which a liquid changes phase to a solid

Question 42

Boiling point

Answer 42

the temperature at which a liquid changes phase to a gas